Access to data across multiple filesystems is a significant concern for computer users. Users may encounter difficulties when trying to access filesystems supported in a source system but not supported in an accessing system. For example, an older version of an operating system may be unable to access a volume created in a newer version of the operating system because of new features present in the filesystem of the newer version, which render the newer version inaccessible to the older version.
Attempts to access volumes containing a filesystem incompatible with the accessing device may have unintended consequences for users. The accessing system may not recognize the filesystem of the source system and present the volume as “raw,” or apparently unrecognized. At the least, the accessing system may not be able to determine that data is present on that volume. At worst, an accessing system which fails to recognize the volume may prompt the user to reformat the entire volume, causing loss of the data in the volume.
Furthermore, loading of special drivers or software to allow access to a volume ordinarily unrecognizable by an operating system has traditionally required execution in kernel mode, thus running afoul of security policies which limit execution to user mode.